🩱 The Ultimate Supply List for Sewing Your Own Swimwear (Without Losing Your Mind)
Ever stood in front of a pile of stretchy fabrics thinking, “Which one of you lovely nightmares becomes a bikini?” 😅
You’re not alone. I’ve chatted about sewing underwear, crafting felt toys, and even making ornaments — but somehow, I’ve never spilled the tea on what supplies you actually need to make swimwear.
So let’s fix that today before another meter of spandex gets sacrificed to the sewing gods.
🧵 Meet Your Swimwear Fabrics (a.k.a. The Real MVPs)
First things first — the fabric.
If your swimwear has side seams and isn’t adjustable (you know, the classic one-piece or simple bikini), then let me save you from heartbreak right now:
👉 You must use four-way stretch fabric!!!
No shortcuts. No “maybe it’ll stretch enough.” It won’t.
Otherwise, you’ll be stuck with a swimsuit that won’t go past your hips. True story.
1. Four-Way Stretch Mesh (Spandex)
Most people think mesh is just for lingerie. But hey, you’re the designer — go wild!
This fabric stretches like a dream and forgives all your tiny cutting or sizing mistakes (been there 🙃).
Use it:
- As a transparent back on a two-piece (looks stunning).
- Layered over printed fabric to give that dreamy, soft-filter vibe.
You can double it up for structure or keep it light for flexibility. Either way — it’s magic.
2. Polyester or Lycra
These are the classic swimwear heroes — colourful, wild, and endlessly creative.
Want floral? Leopard? Metallic shine? Fake leather vibes? They’ve got you covered.
Mix and match half-print, half-solid designs — it instantly makes your piece look designer-level.
💡 Tip: Metallic and faux-leather Lycra look gorgeous but can feel warm or sticky in water. Keep them for beach lounging rather than actual swimming.
And if you’re just planning to sip lemonade on the sand (no judgment here 🍹) — even four-way stretch velvet can join the party. It screams “luxury,” but it’s not the best swimmer, let’s be honest.
💪 Elastics – Your Swimwear’s Secret Weapon
If you’ve ever wondered why ready-made swimwear feels “snug but comfy,” it’s all about elastic choice.
1. Fold-Over Elastic
My beginner-friendly favourite. Just sandwich your fabric inside, fold, sew, and done. No rocket science involved 🚀
It’s forgiving, simple, and gives a polished edge every time.
2. Flat Elastic
Now this one’s the grown-up version — a bit more technical, but once you get it, you’ll never go back.
It’s usually 0.5–1 cm wide, and you sew it straight to the wrong side of your fabric edge (waist, leg holes, armholes, etc.).
First, stitch it down with your overlocker (or regular zigzag if that’s what you’ve got), then fold it inside once more and topstitch it again with a zigzag.
That way, your elastic ends up hidden between two fabric layers — totally clean and professional looking.
Yes, it’s more steps and needs some testing with your machine tension, but the result is chef’s kiss 💋
And if you’re panicking like, “But I don’t have an overlocker!”, calm down — you can absolutely do it on a normal sewing machine.
See How To Sew Beautiful Lingerie Without a Serger — same logic applies to swimwear to
✨ Hardware – Because Details Make the Designer
I’m a hardware addict — rings, sliders, gold bits… give me all of it 😍
Most people say “that’s for underwear,” but honestly, rules are overrated.
Adjustable straps are life-savers. Whether you gain or lose a little weight, you can tweak the fit instead of retiring your creation.
The trick is to choose proper strap elastic, not the cheap flimsy stuff that warps inside sliders (learned that lesson the hard way).
Picking Sizes:
- Most underwear uses 10 mm elastic, but if you’re blessed with more curves (L or XL+), go for 12–14 mm.
- Always match your rings and sliders to the width of your strap elastic. Mis-matching looks messy and just doesn’t sit right.
🎥 Bonus: On my YouTube channel, I show five ways to make straps, including my favourite method with red velvet fabric (don’t worry, it’s easier than it sounds) 👇.
🧩 Patterns – The Real Make-or-Break Moment
You can’t skip this one — even the prettiest fabric can’t save a bad pattern.
- Tested patterns only! Look for real feedback or photos from makers who’ve used them.
- Be cautious with random “AI-generated” freebies — sizing disasters await 😬
- And please… patterns without markings? Torture. It’s like sewing with LEGO at 2 am.
If your design has non-adjustable side seams, feedback on fit is everything. Make sure the pattern’s measurements match real human sizes, not alien proportions.
If you’d like some tried-and-tested options, you can peek at my swimwear sewing pattern collection — every design there is made for stretch fabrics, tested by real makers, and personally tried by me before it’s ever released to the public (no AI-generated chaos, promise 😉)
⚙️ Quick Tip Before You Pick Your Fabric
Now, if your swimwear has straps — especially adjustable ones — you can sometimes get away with using a two-way stretch fabric instead of four-way.
Normally, I’d never advise it (I can already hear future tears at the sewing machine 😅), but adjustable straps can compensate for that missing stretch.
So if you fall in love with a fabric that’s only two-way stretch and you just have to use it, go for it — as long as your design lets you adjust the fit.
And if you’re not sure how to tell which fabric you’ve got in your hands, don’t guess!
Read How to Instantly Tell the Difference Between 2-Way and 4-Way Stretch — it explains exactly how to recognise both and will save you from a major “why won’t this go over my hips” meltdown. 🙈
🧠 Pro Tip: Turn Your Undies Into Swimwear (Yes, Really)
Who said a swimwear pattern has to be a swimwear pattern?
I’ve turned my Top Enigma (originally a gym top) into a swim top — and my thong Enigma panties into matching bottoms.
The secret? Same fabric = instant matching set.
I used to drag three outfit changes to the gym-spa complex — gym gear, swimsuit, casual clothes.
Now? I just wear my Enigma set, peel off the leggings, and boom — ready for the sauna. 🧖♀️
No more 10,000 outfit swaps. Pure freedom!
So next time you see a lingerie pattern, don’t think lace and ribbons — think Lycra and pool days. Sketch the outline, imagine it in swim fabric, and go for it.
🧵 Let’s Wrap It Up (Without Tangling the Thread)
So yeah, not every pattern out there is a masterpiece — and trust me, some can test your patience to dangerous levels. 😅
Make sure it’s a reliable, well-tested pattern, especially if it has side seams and no adjustability.
You don’t want to waste your best fabric, elastic, and half a Sunday just to end up with something that doesn’t even fit your cat.
And here’s the secret most people ignore: any lingerie pattern can become a swimwear pattern.
Swap lace for Lycra, pick matching tops and bottoms, and boom — you’ve got a bikini set that looks store-bought but fits you perfectly.
Don’t be afraid to mix gym tops with panty patterns — if the shapes work, use them.
You’re the designer. You decide the rules.
And before you even ask — yes, you can sew swimwear without an overlocker.
If you’re curious how, go read How To Sew Beautiful Lingerie Without a Serger —
ignore the word “lingerie,” because the same steps work beautifully for swimwear too.
See you there — and may your stitches stretch perfectly and never snap. 💙
